controlling execution order of servlet filters

[Angus Parvis]

Hi,

I am developing a web-application using Tomcat 5. Most of the user's
requests invoke servlet filters before the request is passed to the
servlet itself.

What I want to do is to chain up several filters. For example when the
users requests /MyServlet the filter-chain should be like this:

LocalizationFilter -> AuthenticationFilter -> /MyServlet

MyServlet generates specialized XML data. On the "way back" I want to
add some general XML data (PageGenerationFilter) and then transform the
whole document (XSLTFilter). The servlet and it's filters should be
chained like this:

/MyServlet -> PageGenerationFilter -> XSLTFilter

What I want is to control the order of the filters to be invoked - to
asure, that the XML data is complete before the transformer is invoked.

The simplest quick'n'dirty solution to this problem would be to unite
the PageGenerationFilter with the XSLTFilter - but I think there has to
be a way to control the invocation order of servlet filters. Can you
tell me how to do this?

Please don't direct me to docs or tutorials unless they are really
helpful. I spent quite a while searching the internet, but couldn't find
useful information.

Thanks for every help,

Greetings,

Angus

 

[Angus Parvis]

I've found an answer to my question. For all those, who are interested:

"After writing the filters, they need to be defined and mapped to a URL
pattern in the deployment descriptor. The order in which they are
defined matters. The container will execute the filters in the order in
which they are defined."

You can read it at
http://www.onjava.com/pub/a/onjava/2001/05/10/servlet_filters.html?page=3
in the first paragraph.

Yahoo